Do you use the magic tool called "Debugger"? Have you checked the values of that variable that you are having the exception from? Which line of the code you are having the exception? Let us know these. Dont expect us to be a physcic!!!

It brings me to a good idea. We could create universal FAQ of very few questions like that and warn all inquirers that if they ask exact same question again, their post will be treated as spam. Honestly.

Very few questions like that, really. Incompatibility between type X and string (no implicit conversion), referencing null pointer, index out of range, maybe even the use of PictureBox for something dynamic/interactive...

Yeah Sergey, that sounds about right. We can create a FAQ like one default thing to do in these kind of particular situations. It surely will be beneficial but like as always there will be ignorant/typical members who will not take the time check that FAQ even it exists. Such people as "i need this code", "i want you to do my project"..etc.

So we should take that into consideration :) We can suggest this to Chris Maunder and if he approves I am in.

Yes. And, by the way, this is a pretty usual practice. For example, if you use some publicly open issue management system access for some project, the "create ticked" action starts with the warning that the contributor to the tickets should first look for similar tickets; for this purpose, a search engine is provided. But we already have it, our goal is just to get rid of those copies of so frequent questions, those which have been repeated thousands of times...
—SA

I know exactly what you meant, I'm not the thundering idiot you think I am and I'm perfectly capable of understanding what you were saying. However, there is already an excellent mechanism in place here on Code Project that is absolutely perfect for doing this, and would be of more benefit than just for the narrow scope of Q and A.